Furnace



April 29, 1930.

A. F. HALL FURNACE Filed Sept. ,15, 1921 3 Sheets-Sheet l 2/ W77 5 a F/7 5 3 Patented Apr. 29, 1930 UNITED STATES ARTHUR F. HALL, OF

PHILADELPHIA, PEN sYL'V IA, AssIsNon T HALL ARCH ooMPANY, orPHILADELPHIA, PENNsYLvANIA,

A CORPORATION OF DELAWARE EUnNAoE Application filed September 15, 1927.Serial No. 219,647.

My invention relates to improvements in furnaces, furnace walls and thelike and it has for its object to provide an improved. furnace and animproved furnace wall construction.

Another object of my invention is to provide an improved furnace wallbuilt up from molded block units and comprising inner and outer wadsections that are interlocked in in spaced apart relationship so thatthey mutually support each other and provide an air space between themthrough which air is forced and then delivered in a pre-heated state tothe furnace as in my co-pending application Serial Number 108,969, filedApril The invention resides in certain features of construction and modeof operation set forth in the following description, the several novelfeatures thereof being particularly pointed out and defined in theclaims at the close of the description.

In the accompanying drawings Figure 1 is an elevation of a portion of afurnace wall constructed in accordance with my invention.

Figure 2 is a view in horizontal section on line 2-2 of Fig. 1. V

Figure 3 is a view in vertical section on line 33 of Fig. 1.

Figures 4, 5 and 6 are details of one of the two kinds of blocksconstituting the outer wall section of my improved construction.

Figure 7 is a detail of the locking pin hereinafter described.

Figure 3 is a sectional plan View of a portion of a furnace wallconstructed in accordance with my invention, but differing in somerespects-from the wall shown in Figs. 1 and 2.

Figure 9 is a perspective view illustrating a feature of the wall shownin Fig. 8 and is hereinafter more fully described.

Figure 10 is a vertical sectional view on the line 10 of Fig. 8,including also a portion of the floor of the furnace.

Figure 11 is a plan view of one of the floor blocks hereinafterdescribed.

Figures 12, 13 and 1a are details hereinafter described.

My present invention is herein shown as embodied in an oil burningfurnace, like that shown and described in my prior application referredto but it will be obvious to those skilled in this art that. it is notlimited in this respect and may be embodied in furnaces of other kinds.It may be constructed, as in that application, with side, front and rearwalls and in the case of an oil burning fur-- nace, said front wall maybe provided with a burner port and cone or register, as usual.

The present construction is characterized by the provision of an airspace 8 within, and

throughout the extent of, the wall of the furnace. This air space isprovided'by building the wall in two sections comprising an outer wallsection 13 and an inner wall section 12, and it is an important featureof the invention that the inner wall section 12 is made from moldedblocks of carborundumorany other suitable material having high thermalconductivity, the necessary tensile strength and a high resistance tofusion, while the outer wall section 13 is built up from blocks ofmolded diatomaceous earth (kieselguhr) or any other suitable refractorymaterial having low thermal conductivity and high heat insulatingproperty. The two materials mentioned,.however, viz, carborunduni forthe inner wall section and diatomaceous earth for the outer wallsection, I regard as prefer able as theygive to said two sections thedesired characteristics to a high degree.

As explained in my prior application, above referred to, air is forcedthrough the air space 8 of the wall under pressure from an inlet at oneend of that air space and, after traversing the latter is delivered intothe furnaceto support combustion from the opposite end thereof. It will,therefore, be clear that as the air passes through the wall it is heatedby the inner carborundum wall section 12 which is exposed to the flamesof the furnace, and 1s therefore delivered into the furnace in a preheated state thereby increasing the efficiency of the furnace beyondthat obtained when the furnace is supplied with air that is notpreheated.

The inner wall section 12 is constructed from blocks 14L of carborundumor the like, laid on edge in tiers but staggered so as to break thevertical joints between them, each vertical joint of each course beingpositioned midway of the block immediately above it and midway of theblock immediately below it. At each corner of the furnace the twoadjacent inner wall sections are constituted in part, and connected, bya single tier of L- shaped block units 15, of carborundum, which arecommon to both of said inner sections. Alternate blocks of this cornertier occupy positions that are the reverse of the other blocks of thetier thus interlocking the two inner wall sections.

The outer wall section 13is constructed from block units 16 ofdiatomaceous earth or the like laid on edge in tiers, but staggered soas to break the vertical joints, each vertical joint of each coursebeing positioned midway of the block intermediately above it and midwayof the block immediately below it. At each corner of the furnace the twoadjacent outer wall sections are constituted in part and connected by asingle tier of L-shaped block units 17 which are common to bothsections, alternate ones of which occupy reversed positions relativelyto the others.

Each block unit 14, is of rectangular or oblong shape except that at itsmiddle, and upon its inner or air space side, it ismade with aperpendicular lug 14 extending from top to bottom of the block. Thuseach block unit 14 is of symmetrical T-shape in plan, the body of theblock constituting the head of the T and the lug the stem thereof. Thebody of the block may conveniently be made one or two inches thick, forexample, l inches wide and 9 inches long. The body portion of each block16 will have the same width and length as the body of block 14 and itsthickness may be as desire-d, or the same as that of the block 14, viz,2 inches, for examples Each block unit 16 is of symmetrical U-shape inplan being provided at its opposite ends, and upon its inner or airspace side, with perpendicular lugs 17 extending from the top to thebottom of the block as indicated in Fig. 4. It follows that when the twosections of the wall are built up from these-T-shaped and U-shaped blockunits, the lugs of one section.

register vertically and interlock with the lugs of the other, theseveral vertical series of registering lugs providing a multiplicity ofVertical and parallel air channels. The lugs 14 and 16 are preferablyall of one length and in setting up the two wall sections the latterside. From the above description. it will beapparent that the airpassing through the wall on its way to the interior of the furnace willnnpinge upon and pass around the lugs 14 and 16 thereby being caused totravel a'sinuous course which not only thoroughly agitates the air, butbrings it into very intimate contact with the heated carborundum blocks14, the provision of the lugs 14 onthe air space sides of the lattergiving to each block a surface areafor contact with the air much greaterthan would be the case with a flat sided carborundum block. I

A feature of my present invention consists in providing an intermediatelayerof cushioning and heat insulating material such as asbestos millboard 20", or the like, between the outer steel casing 20-and the Wall.

The blocks 16 and 17 of the outer Wall section, orsome of them, aresecured, or fastened, near their middle by bolts 21 to the outer casing.The head of each bolt 21 is outermost and its shank extends through thesteel casing 20, the intermediate cushioning layer 20, and block 16, toapproximately the inner side of the latter where its threaded innerendis provided with a nut 21 The nut 21 is hexagonal and occupies ahexagonal pocket 21 upon the inner side of the block and fits the lattersufficiently to be held thereby against rotation so that the bolt istightened up by application of a wrench to itsouter end. V r

The outer steel casing 20 with the intermediate cushioning layer 2Oserves to protect the outer wall and to reinforce the furnace struc tureagainst the injurious effects of vibration. Also the intermediate layer20" serves to insulate the wall structure from the outer steel casingagainst the transmission of heat and vibrations from one to the other.

The blocks 16 of the outer wall section are 'molded from diatomaceousearth but any other suitable mat ial of low heat conductivity may beemployed if, desired, and a novel feature of the construction of theseblocks con-.

sists in providing each with a suitable reinforcing and strengtheningcore or skeleton'22 of suitable material such as manganese steel. Thisskeleton 22, Figs. 4, 5 and 6, is shown as made with transverse end bars22"" extending into the end lugs 16* and the block 18 provided withsemi-circular grooves 22, one at each side of each luq and near theextremit there-- m m J, I of. 1 he lu 14 or each carborundum block 14all) is molded near its extremity, and at opposite sides thereof, withsemi-circular grooves 14;- which register with the grooves 22 of thelugs 16 immediately above and below it, thereby (o-operating with thelatter to provide passages for pins 23 which positively lock the lugstogether. These lockin pins are flanged at their opposite ends, saidflanges serving to hold the pins against accidental displacement.Preferably the pins 23 are molded from carborundum but they may be madefrom manganese steel or any other suitable material. In Figs. 8 and 10the end terminals 22 of the skeleton frames 22 are disposed upon theends of the lugs of the block and extend transversely from the top tothe bottom thereof. Thus when two blocks 16 are placed end to end theend terminal sockets 22 register and provide a round hole between theblocks for the reception of an articulated locking rod made up of shortsections 24 pivotally connected together by pintles 24. The lugs 1% ofthe carborundum blocks 14: constituting the inner wall section of thestructure illustrated in Figs. 8 and 10, are molded with round verticalholes 14 through them that register with the holes provided by thesocket terminals 22 and receive the articulated rod made up of sections24E. Thus the articulated rod serves as a key to lock the lugs of thetwo wall sectionstogether. The articulated rod loosely iits its holesand sockets and by raising it upwardly any one or more of thecarborundum blocks-normally held by it may be removed when it isnecessary to substitute a new one. The rod 24 is preferably, though notessentially, made sectional as described for the reason that in somecases the space above the furnace is so limited that a one-piece lockingrod could not be lifted far enough. By making the rod in sectionspivotally connected together as described itis flexible laterally andits sections can be folded sidewise as they are raised out of thewallthus permitting removal of the rod in situations where the overheadspace is very limited.

T he end bars 22 of the metal skeleton rein forcing frames 22 are madeat their outer ends, that is, the ends thereof adjacent the outer faceof the block, with corner. terminal bars 22 extending from the top sideof the block to its bottom side, the corner bars 22 of. each block 16fitting against the adjacent corner bars 22 of the two blocks at theopposite ends thereof as shown in Figs. 2 and 8.

At the middle of each metal reinforcing skeleton 22 there is provided ananchor bolt socket 22 providing a hole through the block 16 extendingfrom its inner to its'outer face. This hole is equipped with a lining orbush ing 22 made from the same material as the asbestos mill boardlining 20 for the casing 20, or any other suitable material of low heatconductivity. The pocket 21, Fig. 5, for the nut 21', Fig. 7 being theenlarged inner end of this hole. As will be observed from Figs.

flanged to provide 2, 5 and 7 the inner end of lining 22 is bolt 21. Inthis way the nut and shank of the bolt 21 are well insulated from themetal skeleton frame 22 so that comparatively little heat is transmittedfrom the latter to the bolt. Upon the top and under sides of the outerends of'the sockets 22 of each metal skeleton reinforcement 22 areprovided lugs 22 Figs. 1, 2, a and 6, whose outer faces, together withthe outer end of socket 22, are flush with the outer face of the block,and these lugs 22 which are twice as wide as the corner reinforcing barsor terminals 22, each register, as shown in Fig. 1, with the two endcorner bars 22- that are above or below it, as the case may be. It willthus be observed that when the wall is constructed the weight of theupper blocks 16 is supported or sustained by the metal reinforcementthus relieving the frail body of diatomaceous earth of each block ofinjurious strains and stresses. It will also be observed that the endcorner bars 22 protect and reinforce said body adjacent said corners andthe ends.

If desired provision may be had for positive interlocking engagementbetween the metal reinforcing frames of the blocks 16,-and this may beeffected, as illustrated in Figs. 12, 13 and 14:, by providing the upperends of the corner bars 22 and of the upper lug 22 with studs 33 and 36,respectively, and the lower ends of said corner bars and of the lowerlug 22, with sockets 3e and 35, respectively. Thus, when the blocks 16are assembled in a wall the two lugs 33 at the opposite ends of eachblock 16 will be paired with the lugs 33 at the abutting ends of'the twoadjacent blocks and each pair of lugs 33 will occupy the socket 35 ofthe block immediately above them as indicated in Fig. 12. Also, at eachpair of abutting ends of'the blocks 16 two of the socketsB i will beregistered side by side and provide a recess or notch for the receptionof the lug 36 of the block 16 immediately below said abutting ends.

Figure 13 illustrates a modified form of reinforcing metal frame whereinthe ends of the bar 20, instead of being provided with the sockets 22 ofFigs. 2, 3 and 6, are formed with exposed terminal lugs 37 to occupy thesemi-circular grooves 1 1 of the carborundum blocks immediately aboveand below the bar 22'.

The longer side of each corner blocks 17, Fig. 2, measures the same inlength and width (or height) as the outer side of the block 16 while theshorter side of said corner block is half the length of the longer side.The metal reinforcing skeleton 22 of each corner block 17 is constructedsubstantially the same as the frames 22 of the blocks 16 except that itis of angular shape as shown in Fig. 2 and a seat for the nut 21 offorcing and protecting bars 22 and the anchorobolt socket 22 thereof islocated at the middle of the longer side of the frame;

With the construction shown in Fig. '2 the two relatively perpendicularparts of the outer wall section are connected at the corner of thestructureonly by the tier-of corner blocks 17 which intermesh with theblocks 16 of said two parts. In Figs. 8 and 9 I have illustrated aconstruction wherein the end lugs of the two .vertical rows of mainblocks 16 of the two parts of the wall which inter mesh with theopposite sides of the tier of corner blocks 17, are directly intermeshedand positively interlocked by means of crossshaped pins 26, Fig. 9. Withthis construction, the blocks 16 which are interlocked by thecross-pins'26 are each provided with a skeleton frame 22 provided at oneend with a cross-bar 22 'made at its ends with socket terminals 22 likethe socket terminals 22 of Fig. 2 and it will be clear that in theassembled wall of Fig; 8 the socket members 22 of each block lug soconstructed will be disposed at right angles to the socket members ofthe two block lugs above and below it so that the cross locking pins 26that are placed in the sockets of each lug and its two neighbors, serveto positively lock said lugs together.

As shown inFig. 10 the outside casing is carried under thefloor of thefurnace and forms part of the latter. This floor also includes a bottomor lower layer of blocks 27 which may be madefrom fire clay, diatomaceous earth, or other suitable material. Pref-' erably diatornaceousearth is used for these blocks and in this case each is provided with areinforcingand metal skeleton 28, preferably made from the same materialas the frames 22 and 22. The skeleton frame 28 isimade at each. cornerof the block 27 with a prop to rest upon the casing 20-. These props 30are embedded in legs formed upon the block 27, one ateach cornerthereof, and these legs serve to provide an air space between the casing20 and the blocks 27 through which some of the air that is forcedthrough the walls passes from the air spaceof one wall to the air spaceof the opposite wall. The blocks 27 support a layer of blocks 31arranged on edge, said blocks being made from any suitable heatinsulating material such as diatomaceous earth, fire clay or the like.Upon the top of the blocks 32 of earborundum, or other suitable materialhaving high resistance to fusion. I i

' A furnace constructed in either of the above described manners hasgreat endurance or life and strength, it hasgreat resistance to injurythrough vibration, the loss of heat units through radiation is verysmall if. not, practically whollyreliminated and the efficiency of thefurnace is relatively greatbecause of the fact that, as in myapplication above noted, the air that is supplied to the I furnace isfirst pre-heated by travelling incorporated in a wall.

through the air space of the furnace wall. It

. will also be clear that while the air istravelling through thevertical wall or walls of the furnace it repeatedly impinges upon andpasses around the lugs of the inner carborundum blocks and, therefore,is thoroughly agitated and heated by the latter. Furthermore,

there are no dead air spaces or pockets Within the wall to trap and holdbodies of air.

The blocks of both the inner and outer wall sections are set up withcement between them and as in my application referred to the abuttingsides and ends of the blocks may be grooved or channeled to providepockets to hold bodies of cement'which serve as keys to lock the blocksagainst relative horizontal movement laterally.

After each block 16, or 16", is placed'inposition and fastened there bymeans of its anchor bolt 21, the pocket2l, Fig. 5, is filled in aroundand over the nut 21*, Figs. 2 and 3, with body 50 of plasticdiatomaceous earth or other suitable material having low thermalconductivity of heat.

What I claim is a 1. A block unit forwalls consisting of. a molded bodyof refractory heat insulating material and a reinforcing metal skeletonembedded in said body, said skeleton being made with bars disposed atthesurface of said body and constituting corners'of the block.

2. A block unit for walls consisting of a molded body of refractory heatinsulating material and a reinforcing metal skeleton embedded in saidbody made at its opposite ends with vertical bars disposed at thesurface of said body and constituting theouter end corners of the block.Y 1 g 3. A block unit for walls consisting of a molded body ofrefractory heat insulating,

material and a reinforcin metal skeleton embedded in said body made atits opposite ends and at its middle with portions thereof that extend tothe top and bottom side surfaces of the block toregister with thecorresponding parts of the frames of other blocks when incorporated in awall whereby the load borne by the block is sustained by ners of theblock, said vertical bars being provided at their opposite ends withstuds and sockets, respectively, to interlock with the studs and socketsof other blocks in courses above and below the same when the block is 5.A block unit for walls consisting of a molded body of refractory heatinsulating material and a reinforcing metal skeleton embedded in saidbody made at its opposite ends with vertical bars disposed at thesurface of said body and constituting the outer end corners thereof, andmade near its middle with an anchor bolt socket.

6. A block unit constructed in accordance with claim 5 wherein saidanchor bolt socket is tubular, and including also a tubular-lining forsaid tubular socket made from a nonmetallic material of low heatconductivity.

7. A U-shaped block unit for walls consisting of a molded body ofrefractory heat insulating material and a reinforcing metal skeletonembedded in said body made at its opposite ends with exposed socketterminals constituting parts of the lugs of the block and adapted to beoccupied by locking elements whereby said lugs are connected with thelugs of other blocks.

8. A wall constituted by molded block units and comprising inner andouter wall sections occupying spaced apart relationship to provide anair space between them; vertical rows of lugs upon the inner sides ofboth wall sections integral with the blocks thereof, the lugs of eachvertical row of the outer wall section being intermeshed with the lugsof one of the vertical rows of the inner wall section with the end ofeach lug of each wall section spaced away from the opposite wall sectionto provide a capacious air passage between the two, and a verticallydisposed rod locking the lugs of each vertical row to the lugs withwhich they intermesh.

9. A wall constructed in accordance with claim 8 wherein said rod ismade up of pivotally connected sections and is removable by endwisemovement thereof.

10. A wall built up from molded block units and comprising inner andouter wall sections'spaced apart relatively to provide an air spacebetween them, the blocks of said outer wall section being made fromdiatomaceous earth and the blocks of the inner wall section being madefrom carborundum or the like; metallic reinforcing means incorporated inthe outer wall section, and vertical rows of lugs upon the inner sidesof both wall sections integral with the blocks thereof, the lugs of eachvertical row of the outer wall section being intermeshed with the lugsof one of the vertical rows of the inner wall section with the end ofeach lug of each wall section spaced away from the opposite wall sectionto provide a capacious air passage between the two.

11. A wall built up from molded block units and comprising inner andouter wall sections spaced apart relatively to provide an air spacebetween them, the blocks of said outer wall section being made fromdiatomaceous earth and the blocks of the inner wall section being madefrom carborundum or the like; metallic reinforcing means incorporated inthe outer wall section; vertical rows of vertical rows of the inner wallsection with the end of each lug of each well sectlonspaced I j awayfrom the opposite wall section to provide a capacious a1r passagebetween the two,

and means positively interlocking the inter:

meshed lugs. I y l 12. A wall built up from molded block units andcomprising inner and outer wall sections spaced apart relatively toprovide an air space between them, the blocks of said outer wall sectioneach comprisin a body of refractory heat insulating material and areinforcing metal skeleton embedded in said body and the blocks of theinner wall section being made from carborundum or the like, and verticalrows of lugs upon the air spaced sides of both wall sections integralwith the blocks thereof, the lugs of each vertical row of the outer wallsection being alined and intermeshed with the lugs of one of thevertical rows of the inner wall section with the end of each lug of eachwall section spaced away from the opposite wall section to provide acapacious air passage between the two.

13. A wall built up from molded block units comprising inner and outerwall sec-1 tions spaced apart relatively to provide an air space betweenthem, the blocks of said outer wall section each comprising a body ofrefractory heat insulating material and a reinforc-.

ing metal skeleton embedded therein and the blocks of the inner wallsection being made from carborunclum or the like; a sheet metal casingoutside of said wall; a layer of heat insulating and cushioning materialbetween said sheet metal casing and said wall; anchor boltsextendingthrough said sheet metal casing and engaging the reinforcingmetal skeleton, and vertical rows of lugs upon the inner sides of bothwall sections integral with the blocks,

thereof, the lugs of each vertical row of the outer wall section beingintermeshed with the lugs of one of the vertical rows of the inner wallsection with the end of each lug of each wall section spaced away fromthe op posite wall section to provide a capacious air passage betweenthe two.

14. A refractory structure for a furnace comprising a sectlon ofrefractory block units assembled with aligned longitudinally eX- tendingholes, a spaced section of refractory block units also assembled with aaligned longitudinally extending holes, and rods of refractory materialremovably inserted in said aligned holes and serving to lock theindividual block units in place in their respective sections, and bywithdrawal to permit replacement of any desired block unit.

15. A refractory structure for a furnace comprising a section ofrefractory block units.

assembled with aligned longitudinally extending holes, a spaced sectionof refractory heat insulating block units, and locking rods removablyinserted in the aligned holes of the refractory block units and servingto lock the individual units in place in its section, and

7 by withdrawal to permit replacement of any desired block unit. Signedby me at Boston, county of Suffolk, State of Massachusetts, this 8rd dayof September, 1927.

v ARTHUR F. HALL.

